Field of the Invention
The present invention generally relates to wireless communications networks, such as cellular networks. More particularly, the present invention relates to radio resources management for cellular networks based on LTE/LTE-Advanced technology.
Overview of the Related Art
Evolution of cellular networks has experimented a significant growth in terms of spread and performance, and has recently brought to 3GPP LTE (“Third Generation Partnership Project Long Term Evolution”)/LTE-Advanced standard.
3GPP LTE/LTE-Advanced standard is conceived for allowing data to be high-speed conveyed between a fixed-location transceiver base station or node (e.g., eNodeB) radiating radio waves over a respective land area (network cell) and user equipments (e.g., user terminals, such as cellular phones) within the network cell.
However, due to the growing number of mobile network operators users, LTE/LTE-Advanced cellular networks could fail to meet all users needs for best-effort (e.g., e-mailing and web browsing traffics), multimedia (e.g., audio/video data streaming) and real-time active flows. In fact, multimedia and real-time applications require very high data traffic (e.g., of the order of Mbps), as well as very limiting “Quality of Service” (QoS) (e.g., data packet maximum allowed delivery delay, data packet loss ratio, and jitter), so that their quick and wide spread could make uncontrolled and misconfigured LTE/LTE-Advanced cellular networks inadequate for guaranteeing all users requirements.
In the state of the art, solutions are known aimed at providing improved QoS.
In Giuseppe Piro, Luigi Alfredo Grieco, Gennaro Boggia, and Pietro Camarda, “A Two-level Scheduling Algorithm for QoS Support in the Downlink of LTE Cellular Networks”, Proc. of European Wireless, EW2010, Lucca, Italy, April 2010, a two-level scheduling algorithm is proposed that comprises an upper level (exploiting an approach bused on discrete-time linear close control loop scheme), and a lower level (a proportional fair scheduler).
In Mongha, G.; Pedersen, K. I.; Kovacs, I. Z.; Mogensen, P. E.; “QoS oriented Time and Frequency Domain Packet Schedulers for The Utran Long Term Evolution”, Vehicular Technology Conference, 2008 (DOI: 10.1109/VETECS.2008.557), OFDMA downlink general packet scheduling methods for throughput fairness control among users are disclosed. A decoupled time/frequency domain packet scheduler approach is used, where fairness is controlled with frequency domain metric weighting or Time Domain Priority Set Scheduling (TD-PSS) depending on the number of users in the cell.
In Yunzhi Qian; Canjun Ren; Suwen Tang; Ming Chen; “Multi-service QoS guaranteed based downlink cross-layer resource block allocation algorithm in LTE systems”, Wireless Technology Communications & Signals Processing, 2009 (DOI: 10.1109/WCSP.2009.5371430), a sub-optimal multi-service QoS guaranteed resource block allocation algorithm for downlink LTE system is proposed. All users are classified into three categories according to their channel state information in physical layer and queue state information in data-link layer. Then proposed scheduler assigns resource blocks to predefined three user categories in turns.
In Assaad, M.; “Frequency-Time Scheduling for streaming services in OFDMA systems”, Wireless Days, 2008 (DOI:10.1109/WD.2008.4812849), a frequency time opportunistic (metric-based cross-layer) scheduler is proposed for balancing trade off between fairness and capacity thereby allowing OFDMA systems to handle streaming services without losing much cell capacity.
In Iturralde, Mauricio; Wei, Anne; Yahiya, Tara; Beylot Andre-Luc, “Resource allocation for real-time services using cooperative game theory and a virtual token mechanism in LTE networks”, Consumer Communications and Networking Conference, 2012 (DOI: 10.1109/CCNC.2012.6181183), a two level resource allocation scheme is proposed to enhance QoS for multimedia services in LTE downlink system. The resource allocation scheme combines cooperative game theory (for forming coalitions between flow classes to distribute bandwidth fairly), and a modified EXP-RULE algorithm using a virtual token mechanism.
In Sandrasegaran, Kumbesan; Mohd Ramli, Huda Adibah; Basukala, Riyaj; “Delay-Prioritized Scheduling (PDS) for Real Time Traffic in 3GPP LTE System”, Wireless Communications and Networking Conference, 2010 (DOI: 10.1109/WCNC.2010.5506251), priority-based data packet scheduling is proposed that makes use of data packet delay information and instantaneous downlink channel conditions associated with each user.